An evaluation of patients' willingness to trade symptom-free days for asthma-related treatment risks: a discrete choice experiment.
BACKGROUND
Not taking treatment preferences into account may lead to patients' inappropriate use of asthma treatments. The objective of this study was to quantify these preferences, in terms of risk-benefits trade-offs, for six asthma treatment attributes using a discrete choice experiment (DCE).


METHODS
Adult asthma patients (n = 157) participated in the study. The custom-designed DCE measured preferences for treatment effectiveness (symptom-free days), potential risk (oral thrush and tremor/heart palpitation), ease of use (frequency of daily administration and number of inhalers required), and cost. A nested logit model was used to determine the relative preferences of each attribute, from which the marginal rates of substitution were calculated. Segmented models were used to test for interactions between cost and treatment benefit with socioeconomic status and medication use.


RESULTS
Relationships between preferences and all attributes were in the hypothesized direction. On average, patients were willing to pay an additional $14 per month to receive one additional symptom-free day, and $26, $79, and $112 monthly to avoid one, two, and three annual episodes of oral thrush, respectively. Income and the magnitude of short-acting beta -agonist use also affected treatment preferences.


CONCLUSIONS
Overall, asthma patients desired treatments that offered more symptom-free days, but they were willing to trade days without symptoms in exchange for a reduction in adverse events and greater convenience.
McTaggart-Cowan
Helen M
HM
Department of Health Care and Epidemiology, University of British Columbia, Vancouver, British Columbia, Canada.
Shi
Peilin
P
Fitzgerald
J Mark
JM
Anis
Aslam H
AH
Kopec
Jacek A
JA
Bai
Tony R
TR
Soon
Judith A
JA
Lynd
Larry D
LD
D000328:Adult; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000191:economics; D001249:Asthma / Q000188:drug therapy* / Q000191:economics / Q000523:psychology*; D003362:Cost-Benefit Analysis; D003430:Cross-Sectional Studies; D003657:Decision Making; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D010342:Patient Acceptance of Health Care; D010865:Pilot Projects; D011788:Quality of Life; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires
D018927:Anti-Asthmatic Agents